Journal of the International Society of Sports Nutrition (Dec 2024)

Muscle contraction time after caffeine intake is faster after 30 minutes than after 60 minutes

  • Paweł Pakosz,
  • Mariusz Konieczny,
  • Przemysław Domaszewski,
  • Tomasz Dybek,
  • Oscar García-García,
  • Mariusz Gnoiński,
  • Elżbieta Skorupska

DOI
https://doi.org/10.1080/15502783.2024.2306295
Journal volume & issue
Vol. 21, no. 1

Abstract

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ABSTRACTBackground This study aimed to determine the optimal time point, either 30 or 60 minutes, at which muscle reactivity to caffeine administration is highest. Unlike previous studies that focused on the nervous system response, we employed tensiomyography (TMG) to directly assess the effects of caffeine on muscle fibers.Methods TMG measurements were performed on the gastrocnemius medialis muscle of 42 male athletes who regularly consumed caffeine. Participants received a dose of 6 mg/kg body weight and TMG measurements were taken prior to caffeine intake, as well as 30 and 60 minutes afterward.Results Analysis of TMG parameters including time to contraction (Tc), time delay (Td), and maximal displacement (Dm) revealed that muscles exhibited faster contractions and greater stiffness at the 30-minute mark compared to both pre-caffeine intake and the 60-minute time point. Time exerted a significant main effect on Tc (F(2, 246) = 12.09, p < .001, ή2p = 0.09), Td (F(2, 246) = 3.39, p = .035, ή2p = 0.03), and Dm (F(2, 246) = 6.83, p = .001, ή2p = 0.05), while no significant effect of body side was observed.Conclusions The findings indicate that muscle contraction time (Tc) and delay time (Td) are influenced by the time elapsed since caffeine ingestion, with the fastest responses occurring after 30 minutes. Additionally, a systemic effect of caffeine was observed, as there were no discernible differences in measurements between the two sides of the body. TMG proves to be an effective noninvasive method for assessing muscle responses following caffeine administration.

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